An action of a customer picking up an item placed on a display shelf in a retail store such as a convenience store or a supermarket may indicate that the customer is interested in the item, and if the customer ended up in not purchasing the item despite having picked it up, it may be considered that there might be some problem in item description, way of displaying items, etc. Thus, by analyzing item pick-up actions of customers to pick up items on display shelves, it is possible to obtain information useful in running the store.
To perform such analysis of item pick-up actions of customers, it is necessary to observe the behavior of each customer present in the vicinity of a display shelf and detect item pick-up actions, and in this regard, technology is conventionally known in which image recognition technology is used to detect item pick-up actions of customers from captured images of an area around a display shelf (refer to JP2009-048430A, JP2012-173903A, JP2012-088878A, JP2011-253344A and JP2001-128814A, for example).